1. Field of the Invention
The present invention relates to a fully enclosed and self-contained dumping bay such as may be utilized in metallurgical operations, and particularly, for example, in steelmaking. The dumping bay has among other features, fume collecting provisions for capturing and collecting hazardous fumes emitted within its interior.
2. Description of the Related Art
It is well known that certain metallurgical processing operations emit or generate hazardous, or at least potentially hazardous, fumes and dust. This is particularly the case in the manufacture of leaded steel in which hazardous fumes and dust containing the known carcinogen lead, are emitted.
Significant amounts of lead-containing fumes or dust are emitted when dumping slag from the manufacture of leaded steel. This operation involves transporting an empty or nearly empty ladle, however still containing slag, to an area at which the contents of the ladle are transferred to a slag pot. Typically, this transfer is achieved by tilting the ladle to an inverted position so that slag contained in the ladle falls into the slag pot positioned under the inverted ladle. As will be appreciated, this operation results in the emission of copious amounts of lead-containing fumes, dust, and gases during the dumping operation.
Accordingly, prior artisans have devised numerous fume collecting devices for use with various metallurgical containers such as ladles. In one approach, artisans provided movable fume collecting devices for placement near these containers during dumping operations. For example, in U.S. Pat. No. 3,604,697, Kawama et al. described a movable hood assembly that may be placed over the mouth of a ladle to collect fumes therefrom. Alternatively, Plazier, in U.S. Pat. No. 3,809,376 described a stationary hood that, when a tiltable container positioned underneath the hood is rotated into alignment and engaged with the hood, collects hazardous vapors exhausted from the container. This technique was also adopted by Neuner et al. in U.S. Pat. No. 4,256,289 and by Laimer in U.S. Pat. No. 4,243,208. Yet another approach to collecting fumes is to extend a duct directly to a cover for the particular metallurgical vessel and ensure that the vessel is covered while removing the hazardous fumes from the vessel through the duct. This approach is illustrated in U.S. Pat. No. 4,792,123 to Moser et al. and U.S. Pat. No. 4,836,510 to Weber et al.
Although satisfactory in many respects, there are several disadvantages associated with each approach. The use of a movable hood assembly is undesirable in that the hood must be properly placed alongside the vessel or container of interest. This is not possible if the vessel is still relatively hot. Additionally, after the necessary operations have been performed concerning placement of the hood alongside the vessel and its contents, the hood must be moved away from the vessel. These operations all require additional labor. Furthermore, the use of a movable hood also requires additional hardware and maintenance associated with the components of the hood enabling its selectively movable feature.
If instead, one uses a stationary hood and a rotatable vessel that is engaged with the hood, equipment must be provided to support and maintain alignment between the hood and vessel. The hardware associated with this technique is also relatively expensive. Additionally, precautions must be taken with regard to the extremely high temperatures potentially existing in and around the vessel. This is particularly so due to the very close proximity between the hood and the vessel.
The third approach, i.e. the use of a ducted cover without any other fume collecting provisions, is not feasible when the vessel must be tilted or inverted to transfer its contents to another container. If this approach were utilized in a slag dumping operation, significant amounts of fumes and vapors would escape into the surrounding environment from the uncovered vessel during dumping. Accordingly, in view of the numerous disadvantages associated with each of the prior art approaches to collecting fumes, there is a need for an improved apparatus and technique for collecting fumes during an operation involving the transfer of contents from one metallurgical vessel to another.
Moreover, it would be particularly beneficial to provide protection against the excessive amounts of thermal and radiant energy emitted from a metallurgical vessel and its contents during certain dumping operations. If dumping occurs in a dedicated region or enclosure within a facility, it is burdensome and typically not feasible to incorporate significant amounts of heat resistant material in certain enclosure components such as doors. This is largely due to the high densities and weight of most heat resistant materials such as ceramics. The use of such materials in doors for instance, significantly increases the weight and difficulty in operating those components. Additionally, the hardware associated with such heavy components must be strengthened, thereby further increasing costs. Accordingly, there is a need for a technique and apparatus for providing protection against excessive amounts of thermal and radiant energy emitted during a transfer operation. Specifically, there is a need for eliminating the requirement of incorporating heat resistant materials into enclosure components such as doors.